U.S. patent application number 10/985868 was filed with the patent office on 2005-05-12 for apparatus and method for storing/reproducing voice in a wireless terminal.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Choi, Kwang-Cheol, Kim, Hyun-Soo, Lee, Jung-Seung, Lee, Nam-Il.
Application Number | 20050101301 10/985868 |
Document ID | / |
Family ID | 34545868 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050101301 |
Kind Code |
A1 |
Kim, Hyun-Soo ; et
al. |
May 12, 2005 |
Apparatus and method for storing/reproducing voice in a wireless
terminal
Abstract
A system and method for recording conversation voice signals in
a wireless terminal. The wireless terminal determines whether a
current conversation state is a silence state or a voice state. If
the current conversation state is a voice state, the wireless
terminal stores packet data. If the current conversation state is a
silence state, the wireless terminal stores information regarding
the number of silence frames.
Inventors: |
Kim, Hyun-Soo; (Yongin-si,
KR) ; Lee, Jung-Seung; (Yongin-si, KR) ; Choi,
Kwang-Cheol; (Gwacheon-si, KR) ; Lee, Nam-Il;
(Suwon-si, KR) |
Correspondence
Address: |
ROYLANCE, ABRAMS, BERDO & GOODMAN, L.L.P.
1300 19TH STREET, N.W.
SUITE 600
WASHINGTON,
DC
20036
US
|
Assignee: |
Samsung Electronics Co.,
Ltd.
|
Family ID: |
34545868 |
Appl. No.: |
10/985868 |
Filed: |
November 12, 2004 |
Current U.S.
Class: |
455/412.1 ;
455/414.1 |
Current CPC
Class: |
H04M 1/656 20130101;
H04M 1/72433 20210101 |
Class at
Publication: |
455/412.1 ;
455/414.1 |
International
Class: |
H04B 001/46 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2003 |
KR |
2003-79939 |
Claims
What is claimed is:
1. A method for recording conversation voice signals in a wireless
terminal, comprising the steps of: determining whether a current
conversation state is a silence state; storing packet data if the
current conversation state is determined to be a voice state; and
storing information regarding the number of silence frames if the
current conversation state is determined to be a silence state.
2. The method of claim 1, wherein the step of determining whether a
current conversation state is a silence state comprises the step
of: determining whether the current conversation state is a voice
state or a silence state according to whether a vocoder rate for a
current transmission frame or a reception frame is higher than a
predetermined value.
3. The method of claim 2, wherein the step of determining whether a
current conversation state is a silence state further comprises the
steps of: detecting a frame having a higher vocoder rate from among
vocoder rates of the transmission frame and the reception frame if
states of the current transmission frame and the reception frame
are both a voice state; and determining whether a current voice
state is a transmission voice state or a reception voice state.
4. The method of claim 3, wherein the step of determining whether a
current conversation state is a silence state further comprises the
step of: setting the current voice state to a previous voice state
if a vocoder rate of the transmission frame is equal to a vocoder
rate of the reception frame.
5. The method of claim 3, wherein the step of determining whether a
current conversation state is a silence state further comprises the
step of: setting the current voice state to a transmission voice
state if a vocoder rate of the transmission frame is equal to a
vocoder rate of the reception frame and the previous voice state is
a transmission voice state.
6. The method of claim 3, wherein the step of determining whether a
current conversation state is a silence state further comprises the
step of: setting the current voice state to a reception voice state
if a vocoder rate of the transmission frame is equal to a vocoder
rate of the reception frame and the previous voice state is a
reception voice state.
7. The method of claim 1, wherein the step of storing information
regarding the number of silence frames comprises the step of
initializing the number of silence frames if the previous voice
state is not a silence state.
8. The method of claim 1, wherein the step of storing information
regarding the number of silence frames comprises the step of
increasing the number of silence frames if the previous voice state
is a silence state.
9. A method for reproducing conversation voice signals in a
wireless terminal that stores a current conversation state and the
conversation voice signals, the method comprising the steps of:
determining whether a current conversation voice frame to be
reproduced is a silence frame according to the stored conversation
state; converting stored packet data into audible sound if the
current conversation voice frame is a voice frame; and turning off
a speaker if the current conversation voice frame is a silence
frame.
10. The method of claim 9, wherein the step of turning off a
speaker comprises the steps of: detecting a number of silence
frames; and turning off the speaker for a time corresponding to the
number of silence frames detected.
11. An apparatus for recording/reproducing conversation voice
signals in a wireless terminal, comprising: a reception part for
demodulating or decoding a digital-converted received radio
frequency (RF) signal into an audible signal and outputting the
audible signal through a speaker included therein; a transmission
part for encoding or modulating user voice signals from a
microphone included therein; a recording controller for outputting
a control signal indicating whether a current conversation state is
a voice state or a silence state; a memory for selectively storing
at least one of a packet data, a silence period, and a flag
according to the control signal; and a reproducing controller for
checking a flag that specifies a current conversation state of data
stored in the memory, selectively decoding the encoded frame,
converting the decoded frame into an audible signal that can be
output through the speaker, and selectively turning the speaker off
and on.
12. The apparatus of claim 11, wherein the recording controller
further comprises: a detection member to detect a frame format from
a demodulated encoded signal output from the reception part and an
encoded signal output from the transmission part; an access member
to access coding rate information of the transmission and reception
frames; and an output member to output a control signal indicating
whether the current conversation state is a voice state or a
silence state.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. .sctn.
119(a) of Korean Patent Application No. 2003-79939 entitled
"Apparatus and Method for Storing/Reproducing Voice in a Wireless
Terminal", filed in the Korean Intellectual Property Office on Nov.
12, 2003, the entire contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to an apparatus and
method for processing signals in a wireless terminal. More
particularly, the present invention relates to an apparatus and
method for storing/reproducing conversation voice signals in a
wireless terminal.
[0004] 2. Description of the Related Art
[0005] A method for storing voice signals during conversations in a
conventional wireless terminal is typically divided into a method
for storing only reception voice signals and a method for storing
both transmission voice signals and reception voice signals using a
separate external device. However, based on the fact that in most
cases, only one of a called party and a calling party talks during
a call, an improved method has been proposed for either measuring
energy for a predetermined period (such as 20 msec) of
transmission/reception voice samples and storing a voice sample
period having an energy value larger than a predetermined
threshold, or determining whether there is voice signal and storing
a voice sample period for which there is a voice signal.
[0006] The conventional method for storing only reception voice
signals is advantageous in that it is simple in implementation and
has a relatively small amount of data to be stored, but this method
is disadvantageous in that it cannot store transmission voice
signals. When transmission voice signals and reception voice
signals are separately recorded using a separate external device in
order to solve such a problem, a hardware structure of the wireless
terminal becomes undesirably complicated.
[0007] When compared with the conventional methods, the improved
method for storing voice sample energy for a predetermined time
(such as 20 msec) of transmission/reception of voice samples or
storing a voice sample period by determining whether there is voice
signal, is more efficient in storing transmission/reception voice
signals. However, because the improved method does not also
consider a silence situation which may frequently occur during a
voice call, it stores unnecessary data. In addition, because the
improved method stores voice samples, it cannot determine whether a
corresponding voice signal is a transmission voice signal or a
reception voice signal, making it impossible to selectively
reproduce voice signals.
[0008] In addition, because a concurrent conversation state is not
taken into consideration, a calling party's voice signal or a
called party's voice signal having higher energy is selectively
recorded and reproduced in a concurrent conversation period, making
it difficult to continuously record/reproduce the conversation.
[0009] Accordingly, a need exists for a system and method for
simultaneously recording transmission/reception voice signals
without requiring a separate external device.
SUMMARY OF THE INVENTION
[0010] It is, therefore, an object of the present invention to
provide an apparatus and method for simultaneously recording
transmission/reception voices (hereinafter referred to as voice
signals) without a separate external device.
[0011] It is another object of the present invention to provide an
apparatus and method for efficiently reproducing voice data while
also considering the occurrence of a frequent silence period.
[0012] It is another object of the present invention to provide an
apparatus and method for securing continuity of previous voice
signals during voice reproduction in a concurrent conversation
state.
[0013] It is yet another object of the present invention to provide
an apparatus and method for separately reproducing transmission
voice signals and reception voice signals.
[0014] In accordance with one aspect of the present invention, a
method is provided for recording conversation voice signals in a
wireless terminal. The method comprises the steps of determining
whether a current conversation state is a silence state, and
storing packet data if the current conversation state is a voice
state. If the current conversation state is a silence state, then
the method comprises steps for storing information regarding the
number of silence frames.
[0015] In accordance with another aspect of the present invention,
a method is provided for reproducing conversation voice signals in
a wireless terminal that stores a current conversation state and
the conversation voice signals. The method comprises the steps of
determining whether a current conversation voice frame to be
reproduced is a silence frame according to the stored conversation
state or if the current conversation voice frame is a voice frame.
If the current conversation voice frame is a voice frame, then the
method comprises steps for converting stored packet data into
audible sound. If the current conversation voice frame is a silence
frame, then the method comprises steps for turning off a
speaker.
[0016] In accordance with yet another aspect of the present
invention, an apparatus is provided for recording/reproducing
conversation voice signals in a wireless terminal. In the
apparatus, a reception part demodulates/decodes a digital-converted
received radio frequency (RF) signal into an audible signal, and
then outputs the audible signal through a speaker included therein.
A transmission part encodes/modulates user voice signals from a
microphone included therein. A recording controller outputs a
control signal indicating whether a current conversation state is a
voice state or a silence state. A memory selectively stores the
packet data, or stores a silence period and associated flag
according to the control signal. A reproducing controller checks a
flag that specifies a current conversation state of data stored in
the memory, selectively decodes the encoded frame, converts the
decoded frame into an audible signal that can be output through the
speaker, and turns the speaker on or off, accordingly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other objects, features and advantages of the
present invention will become more apparent from the following
detailed description when taken in conjunction with the
accompanying drawings in which:
[0018] FIG. 1 is a block diagram illustrating a wireless terminal
according to an embodiment of the present invention;
[0019] FIG. 2 is a detailed block diagram for illustrating an
operation of storing and reproducing voice signals in the wireless
terminal illustrated in FIG. 1;
[0020] FIG. 3A is a flowchart illustrating a method for storing
voice signals according to an embodiment of the present
invention;
[0021] FIG. 3B is a detailed flowchart illustrating the process of
determining the current voice state in FIG. 3A;
[0022] FIG. 3C is a detailed flowchart illustrating the process of
storing a silence flag and information regarding the number of
frames in a silence period in FIG. 3A;
[0023] FIG. 4 is a diagram illustrating an example of a stored
voice data format according to an embodiment of the present
invention; and
[0024] FIG. 5 is a flowchart illustrating a method for reproducing
voice signals according to an embodiment of the present
invention.
[0025] Throughout the drawings, like reference numerals will be
understood to refer to like parts, components and structures.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0026] An exemplary embodiment of the present invention will now be
described in greater detail with reference to the annexed drawings.
In the following description, a detailed description of functions
and configurations incorporated herein and well known to those
skilled in the art, has been omitted for conciseness.
[0027] The present invention discloses a system and method for
determining whether there is a voice (hereinafter referred to as
"voice signal") at a terminal, and to further determine whether a
current terminal state is a transmission state (Tx) or a reception
state (Rx) depending upon voice activity (hereinafter referred to
as "rate information") determined in a voice compression/expansion
device (hereinafter referred to as a "vocoder"), and to then
efficiently store voice data according to the determination result.
The present invention further discloses a system and method for
selectively reproducing the stored voice signals according to the
transmission/reception state, and the transmission voice signals or
reception voice signals.
[0028] FIG. 1 is a block diagram illustrating a wireless terminal
according to an embodiment of the present invention. Although not
illustrated in the drawing but provided as an input signal, a radio
frequency (RF) signal is received via an antenna, down-converted
into an intermediate frequency (IF) signal, and then converted into
a digital signal. Referring to FIG. 1, the digital signal is then
input to a modem 10, and the modem 10 demodulates the digital input
signal and outputs the demodulated signal to a microprocessor unit
(MCU) 20. The MCU 20, if configured to support Code Division
Multiple Access (CDMA) technology, then accesses coding rate
information by detecting a frame format every 20 msec, and
transmits the coding rate information and packet data based on the
information to a vocoder 50.
[0029] In this example, the MCU 20 accesses the coding rate
information every 20 msec because a voice channel frame of a CDMA
forward traffic channel is transmitted every 20 msec. The data rate
information is information indicating a bit rate at which packet
data transmitted from a transmission side was encoded, and is then
recorded in a packet register located in the vocoder 50. The
vocoder 50 decodes input data packets according to the data rate
information recorded in the packet register, and outputs the
decoded data packets as Pulse Code Modulation (PCM) voice data
samples.
[0030] The PCM voice data samples output from the vocoder 50 are
input to a codec 60. The codec 60 converts the voice data samples
output from the vocoder 50 into an analog voice signal. The analog
voice signal is provided to a speaker (SPK) 63 where it is
converted into audible sound.
[0031] An analog voice signal input from a microphone (MIC) 66 is
converted into PCM voice sample data in the codec 60 located on a
path of a reverse traffic channel, and is then encoded at an
appropriate data rate in the vocoder 50 before being transmitted.
The path of the reverse traffic channel is opposite to the path of
the forward traffic channel in operation.
[0032] In a CDMA mobile communication system, a transmission side
encodes voice signals using a vocoder, and converts the encoded
voice signals into a frame format having multiple coding rates
according to the amount of information. For example, a 13 K QCELP
(Qualcomm Code Excited Linear Prediction) vocoder selects one of a
full rate, 1/2 rate, 1/4 rate and 1/8 rate as a coding rate of a
voice signal, and an 8 K EVRC (Enhanced Variable Rate Coder)
vocoder selects one of a full rate, 1/2 rate, 1/4 rate and 1/8 rate
as a coding rate of a voice signal before transmission. Such coding
rate information is stored in a format byte of a packet, and is
comprised of 2 bits. The frame format of voice data always has a
length of 20 msec regardless of the variable coding rate. The
vocoder selects a coding rate according to the amount of voice
information.
[0033] Upon receiving data over a forward traffic channel, a CDMA
terminal detects a format byte in one frame of a voice channel to
detect a coding rate. Such a CDMA terminal then decodes encoded
voice data according to the coding rate information included in the
detected format byte. Encoding and decoding of voice data is
performed by a vocoder in the CDMA terminal, and the vocoder
decodes data packet information in received frame data into voice
signals through a PCM codec according to a QCELP algorithm. The
voice data decoded by the vocoder is reproduced into an analog
voice signal by the PCM codec, and then output to the speaker SPK.
A memory 30 stores various data including voice data, and can be a
flash memory capable of storing data even in a power-off state.
[0034] FIG. 2 is a detailed block diagram for illustrating an
operation of storing and reproducing voice signals in the wireless
terminal illustrated in FIG. 1. Referring to FIG. 2, as described
in conjunction with FIG. 1, a reception voice signal is demodulated
by a demodulator 11 of the modem 10, and the demodulated voice
signal is decoded by a decoder 51 of the vocoder 50, and then
output to the speaker 63. A transmission voice signal input from
the microphone 66 is encoded by an encoder 53 of the vocoder 50,
and the encoded voice signal is modulated by a modulator 13 of the
modem 10.
[0035] A recording controller 21 in the MCU 20 determines whether a
corresponding voice signal is a transmission voice signal or a
reception voice signal, and controls switches 71 and 72 according
to the determination result when storing voice packets output from
the demodulator 11 of the modem 10 and the encoder 53 of the
vocoder 50 in the memory 30. A reproducing controller 23 in the MCU
20 controls switches 73 and 74 such that packet data stored in the
memory 30 is separately reproduced into transmission voice signals
and reception voice signals, or simultaneously reproduced.
[0036] A detailed operation of the MCU 20 will now be described in
greater detail herein below with reference to FIGS. 3A to 5. FIG.
3A is a flowchart illustrating a method for storing voice signals
according to an embodiment of the present invention. The voice
storing method of FIG. 3A is controlled by the recording controller
21 illustrated in FIG. 2.
[0037] Referring to FIG. 3A, in step 300, the recording controller
21 initializes a previous voice state parameter and a current voice
state parameter. In step 310, the recording controller 21 detects
information regarding a rate for a current voice frame (20 msec)
and voice packet, and determines in step 320 whether the current
voice signal to be stored, based on the detected information, is a
transmission voice (Tx), reception voice (Rx), or no-voice
(Silence).
[0038] In step 330, the recording controller 21 determines whether
the current voice state indicates silence. If it is determined in
step 330 that the current voice state does not indicate silence,
the recording controller 21 stores packet data and also stores a
voice flag and rate information in step 340. However, if it is
determined in step 330 that the current voice state indicates
silence, the recording controller 21 stores a silence flag and
information regarding the number of frames in a successive silence
period in step 350. Thereafter, in step 360, the recording
controller 21 sets the previous voice state to the current voice
state, and then returns to step 310.
[0039] A basic data storing process collects rate information of
transmission/reception data and packet data processed in the
current frame, determines whether a called party currently talks or
a calling party currently talks according to the rate information
of transmission/reception voice signals, and stores voice data of
the party who is currently talking according to the determination
result.
[0040] In this case, two exceptional situations can happen. A first
case can occur where both the calling party and the called party
are not talking, and a second case can occur where both the calling
party and the called party are talking.
[0041] In the first case, because there is no
transmission/reception voice signal, it is not necessary to store
data. In this state, the wireless terminal is allowed to store only
the information indicating that the current frame has no voice
signals as described above. Also, as the first case will happen
over several 20-msec frames, the wireless terminal is allowed to
store only the information regarding the number of frames if there
is no voice frame. If rate information indicates a full rate, 1/2
rate and 1/4 rate, there is high probability that corresponding
data is voice signals, such that the wireless terminal should
preferably perform voice processing. However, if rate information
indicates a 1/8 rate, the wireless terminal regards a corresponding
period as a silence period.
[0042] In the second case corresponding to a concurrent
conversation state and taking the continuity of voice signals
stored in a previous frame into consideration, the wireless
terminal stores transmission data if the previous frame is a
transmission frame, and stores reception data if the previous frame
is a reception frame.
[0043] FIG. 3B is a detailed flowchart illustrating the process of
step 320 for determining the current voice state in FIG. 3A.
Referring to FIG. 3B, in step 321, the recording controller 21
determines whether a transmission vocoder rate is higher than a 1/8
rate. If it is determined in step 321 that the transmission vocoder
rate is higher than a 1/8 rate, the recording controller 21
determines in step 322 whether a reception vocoder rate is higher
than a 1/8 rate. If it is determined in step 322 that the reception
vocoder rate is higher than a 1/8 rate, the recording controller 21
compares the transmission vocoder rate with the reception vocoder
rate in step 323. If it is determined in step 323 that the
transmission vocoder rate is higher than the reception vocoder
rate, the recording controller 21 then sets the current voice state
to the transmission state in step 324. However, if it is determined
in step 323 that the transmission vocoder rate is not higher than
the reception vocoder rate, the recording controller 21 determines
in step 325 whether the transmission vocoder rate is equal to the
reception vocoder rate. If it is determined in step 325 that the
transmission vocoder rate is equal to the reception vocoder rate,
the recording controller 21 determines in step 326 whether a
previous voice state is a transmission state. If it is determined
in step 326 that the previous voice state is a transmission state,
the recording controller 21 then sets the current voice state to
the transmission state in step 324. However, if it is determined in
step 326 that the previous voice state is not a transmission state,
the recording controller 21 sets the current state to a reception
state in step 327.
[0044] However, if it is determined in step 321 that the
transmission vocoder rate is not higher than a 1/8 rate, the
recording controller 21 determines in step 330 whether the
reception vocoder rate is higher than a 1/8 rate. If it is
determined in step 330 that the reception vocoder rate is higher
than a 1/8 rate, the recording controller 21 sets the current voice
state to the reception state in step 327. However, if it is
determined in step 330 that the reception vocoder rate is not
higher than a 1/8 rate, the recording controller 21 sets the
current voice state to a silence state in step 329.
[0045] FIG. 3C is a detailed flowchart illustrating the process of
step 350 for storing a silence flag and information regarding the
number of frames in a silence period in FIG. 3A. Referring to FIG.
3C, in step 351, the recording controller 21 determines whether a
previous voice state is a silence state. If it is determined in
step 351 that the previous voice state is a silence state, the
recording controller 21 increases a silence frame counter value by
1 in step 352, and then updates a silence frame counter with the
increased silence frame counter value in step 353. However, if it
is determined in step 351 that the previous voice state is not a
silence state, the recording controller 21 initializes the silence
frame counter to `1` in step 354, and then stores the initialized
silence frame counter value and a silence flag in step 355.
[0046] FIG. 4 is a diagram illustrating an example of a stored
voice data format according to an embodiment of the present
invention. Referring to FIG. 4, in a voice period, a voice flag
indicating whether a corresponding voice signal is a transmission
voice signal or a reception voice signal, rate information, and
packet data based on the rate, are each stored in sequential order.
By storing the voice flag which is capable of distinguishing
transmission voice signals from reception voice signals in this
way, it is possible to selectively reproduce transmission voice
signals, reception voice signals, or transmission/reception voice
signals according to a user's choice. In a silence period, a
silence flag and information regarding the number of successive
frames are stored. Because a wireless terminal does not store
unnecessary data in the silence period, the wireless terminal can
more efficiently use and manage it's memory.
[0047] FIG. 5 is a flowchart illustrating a method for reproducing
voice signals stored in the format illustrated in FIG. 4. Referring
to FIG. 5, in step 500, the reproducing controller 23 of the
wireless terminal reads flag information of data stored in the
memory 30, and determines in step 510 whether a current frame is a
voice frame. If it is determined in step 510 that the current frame
is a voice frame, the reproducing controller 23 proceeds to steps
520 and 530, where it delivers stored packet data to a decoder 55
of the vocoder 50, and the decoder 55 decodes the packet data and
outputs the decoded voice data to the speaker 63. However, if it is
determined in step 5 10 that the current frame is a silence frame,
the reproducing controller 23 turns off the speaker 63 in step 540
for a time corresponding to the number of successive silence
frames, thereby reproducing voice signals while maintaining
continuity of voice reproduction.
[0048] As can be understood from the foregoing description, the
wireless terminal according to embodiments of the present invention
can simultaneously record transmission/reception voice signals
without a separate external device, and more efficiently store
voice data by detecting frequent silence periods. In addition, in a
concurrent conversation state, the wireless terminal continuously
reproduces voice signals thereby increasing the accuracy of voice
reproduction, and can simultaneously or separately reproduce
transmission and reception voice signals.
[0049] While the invention has been shown and described with
reference to certain exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims.
* * * * *